WATERSHED MODELLING OF MALIR RIVER BASIN TO EVALUATE THE SURFACE WATER POTENTIAL IN KARACHI: A GIS PERSPECTIVE Muhammad Irfan Thesis Submitted in partial fulfillment of the Degree of Doctor of Philosophy in GIS DEPARTMENT OF GEOGRAPHY UNIVERSITY OF KARACHI KARACHI 2017 i BOARD OF ADVANCED STUDIES AND RESEARCH UNIVERSITY OF KARACHI CERTIFICATE This is to certify that Mr. Muhammad Irfan has completed his dissertation for the degree of Doctor of Philosophy under my supervision on: “WATERSHED MODELLING OF MALIR RIVER BASIN TO EVALUATE THE SURFACE WATER POTENTIAL IN KARACHI: A GIS PERSPECTIVE” The completed work is an applied research in the domain of sustainable water resource management. It is for finding the local surface water potential and a possible way of water harvesting for cultivation and groundwater recharge in Karachi region. It is a multi- disciplinary study, having great socio-economic impacts and highly useful for geospatial scientists, planners, environmental engineers and policy makers. It is hoped that in future, identified outcomes will be studied on more technical and economical ground for implementation and similar approach of local water resource harnessing will be adopted in other parts of the country. I wish him success in his future endeavors. _______________________ Dr. Syed Jamil Hasan Kazmi Meritorious Professor, Department of Geography, University of Karachi ii BOARD OF ADVANCED STUDIES AND RESEARCH UNIVERSITY OF KARACHI DECLERATION I, Muhammad Irfan Son of Muhammad Salahuddin hereby declare that no part of the work presented by me has been plagiarized from anywhere. Proper references are cited wherever necessary. I understand that the university reserves the right to cancel the degree if any of the above declaration is proved false before or even after the award of degree. Signature of the candidate: Name of the candidate: Muhammad Irfan Watershed Modelling of Malir River Basin to Title of the Thesis: Evaluate the Surface Water Potential in Karachi: A GIS Perspective Degree: Ph.D. Department/ Subject : GEOGRAPHY (GIS) Date: iii Table of Contents 1 INTRODUCTION ...................................................................................................... 1 1.1 Background ...................................................................................................... 1 1.2 The Problem ..................................................................................................... 4 1.3 General Objective ............................................................................................ 5 1.3.1 Specific objectives ................................................................................... 5 1.4 Study Area ........................................................................................................ 6 1.4.1 Physiography ............................................................................................ 6 1.4.2 Climate ..................................................................................................... 11 1.4.3 Soils and Geology .................................................................................. 11 1.5 Significance of the Study .............................................................................. 12 1.6 Organization of Thesis .................................................................................. 13 2 REVIEW OF LITERATURE .................................................................................... 14 2.1 Location .......................................................................................................... 14 2.1.1 Water Resources for Karachi ................................................................ 14 2.1.2 Surface Storm Water Resources ........................................................... 15 2.1.3 Ground Water Resources ...................................................................... 18 2.2 Problem .......................................................................................................... 21 2.2.1 Rising Water Demand ............................................................................ 24 2.2.2 Shortage of Water ................................................................................... 24 2.2.3 Urbanization ............................................................................................ 24 2.2.4 Rural Water Resources .......................................................................... 24 2.2.5 Climate Change ...................................................................................... 25 2.2.6 Flooding .................................................................................................. 27 2.2.7 Waste of Rain Water ............................................................................... 27 2.3 Techniques ..................................................................................................... 28 2.3.1 GIS and Remote Sensing ....................................................................... 28 2.3.2 Hydrological Modeling ........................................................................... 29 iv 2.3.3 Run-off Potential and Simulation .......................................................... 31 2.3.4 Multi-Criteria Analysis ............................................................................ 33 2.3.5 Dam Site Selection ................................................................................. 34 3 MATERIALS AND METHODS ............................................................................... 36 3.1 Conceptual Framework ................................................................................. 36 3.2 Data and its Sources ..................................................................................... 38 3.2.1 Data I: Published Data ............................................................................ 38 3.2.2 Data II: Field Data ................................................................................... 39 3.2.3 Geo-Database Development .................................................................. 39 3.2.4 Spatial-Referencing ................................................................................ 40 3.2.5 Remotely Sensed Data ........................................................................... 40 3.2.6 Topographic Maps .................................................................................. 42 3.2.7 Thematic Maps ........................................................................................ 43 3.2.8 Climatic Data ........................................................................................... 51 3.3 Data Pre-Processing ...................................................................................... 51 3.3.1 DEM Reconditioning .............................................................................. 51 3.3.2 Fill Sinks .................................................................................................. 52 3.3.3 Geometric Correction ............................................................................. 52 3.3.4 Satellite Data Processing and Enhancement ....................................... 52 3.4 Hydrological Modeling .................................................................................. 53 3.4.1 ArcHydro Data Model ............................................................................. 53 3.4.2 Terrain Processing ................................................................................. 54 3.4.3 Watershed Processing ........................................................................... 55 3.4.4 HEC-GeoHMS Data Model ...................................................................... 55 3.4.5 Rainfall Run-Off Modeling ...................................................................... 55 3.4.5.2 SCS-Curve Number Method ............................................................... 56 3.4.6 Curve Number Evaluation for the study area ....................................... 57 3.4.7 Reclassification of LULC and Soli Map to Hydrologic Conditions .... 57 3.4.8 Reclassification of Soil map to Soil Group .......................................... 58 v 3.4.9 Building up Runoff Depth Map .............................................................. 58 3.5 Decision making and RWH site selection.................................................... 58 3.5.1 Problem Definition .................................................................................. 59 3.5.2 Identification and Selection of Criteria ................................................. 59 3.5.3 Evaluating Consistency of Pairwise comparison ................................ 63 3.5.4 Selection of Criteria Choices ................................................................. 64 4 RESULTS AND DISCUSSION ............................................................................... 69 4.1 Malir River Catchment Analysis ................................................................... 69 4.1.1 Catchment Area ...................................................................................... 69 4.1.2 Stream Network ...................................................................................... 70 4.1.3 Drainage Density .................................................................................... 71 4.1.4 Topography ............................................................................................. 74 4.1.5 Land use and Land cover ...................................................................... 77 4.2